Integrated touch screen

ABSTRACT

Displays with touch sensing circuitry integrated into the display pixel stackup are provided. An integrated touch screen can include multi-function circuit elements that can operate as circuitry of the display system to generate an image on the display, and can also form part of a touch sensing system that senses one or more touches on or near the display. The multi-function circuit elements can be, for example, capacitors in display pixels that can be configured to operate as storage capacitors/electrodes, common electrodes, conductive wires/pathways, etc., of the display circuitry in the display system, and that may also be configured to operate as circuit elements of the touch sensing circuitry.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/943,669, filed Jul. 16, 2013 and published on Nov. 14, 2013 as U.S.Patent Publication No. 2013-0300953, which is a continuation of U.S.patent application Ser. No. 13/717,593, filed Dec. 17, 2012 and issuedon Aug. 6, 2013 as U.S. Pat. No. 8,502,799, which is a divisional ofU.S. patent application Ser. No. 13/527,470, filed Jun. 19, 2012 andissued on Jan. 29, 2013 as U.S. Pat. No. 8,363,027, which is acontinuation of U.S. patent application Ser. No. 12/545,649, filed Aug.21, 2009 and issued on Jul. 10, 2012 as U.S. Pat. No. 8,217,913, whichclaims the benefit of U.S. Provisional Application No. 61/156,463, filedFeb. 27, 2009, and U.S. Provisional Application No. 61/149,340, filedFeb. 2, 2009, the contents of which are incorporated by reference hereinin their entirety for all purposes.

FIELD OF THE DISCLOSURE

This relates generally to displays including display pixel stackups, andmore particularly to touch sensing circuitry integrated into the displaypixel stackup of a display.

BACKGROUND OF THE DISCLOSURE

Many types of input devices are presently available for performingoperations in a computing system, such as buttons or keys, mice,trackballs, joysticks, touch sensor panels, touch screens and the like.Touch screens, in particular, are becoming increasingly popular becauseof their ease and versatility of operation as well as their decliningprice. Touch screens can include a touch sensor panel, which can be aclear panel with a touch-sensitive surface, and a display device such asa liquid crystal display (LCD) that can be positioned partially or fullybehind the panel so that the touch-sensitive surface can cover at leasta portion of the viewable area of the display device. Touch screens canallow a user to perform various functions by touching the touch sensorpanel using a finger, stylus or other object at a location oftendictated by a user interface (UI) being displayed by the display device.In general, touch screens can recognize a touch and the position of thetouch on the touch sensor panel, and the computing system can theninterpret the touch in accordance with the display appearing at the timeof the touch, and thereafter can perform one or more actions based onthe touch. In the case of some touch sensing systems, a physical touchon the display is not needed to detect a touch. For example, in somecapacitive-type touch sensing systems, fringing fields used to detecttouch can extend beyond the surface of the display, and objectsapproaching near the surface may be detected near the surface withoutactually touching the surface.

Capacitive touch sensor panels can be formed from a matrix of drive andsense lines of a substantially transparent conductive material, such asIndium Tin Oxide (ITO), often arranged in rows and columns in horizontaland vertical directions on a substantially transparent substrate. It isdue in part to their substantial transparency that capacitive touchsensor panels can be overlaid on a display to form a touch screen, asdescribed above. However, overlaying a display with a touch sensor panelcan have drawbacks, such as added weight and thickness, additional powerrequired to drive the touch sensor panel, and decreased brightness ofthe display.

SUMMARY

This relates to touch sensing circuitry integrated into the displaypixel stackup (i.e., the stacked material layers forming the displaypixels) of a display, such as an LCD display. Circuit elements in thedisplay pixel stackups can be grouped together to form touch sensingcircuitry that senses a touch on or near the display. Touch sensingcircuitry can include, for example, touch signal lines, such as drivelines and sense lines, grounding regions, and other circuitry. Anintegrated touch screen can include multi-function circuit elements thatcan form part of the display circuitry designed to operate as circuitryof the display system to generate an image on the display, and can alsoform part of the touch sensing circuitry of a touch sensing system thatsenses one or more touches on or near the display. The multi-functioncircuit elements can be, for example, capacitors in display pixels of anLCD that can be configured to operate as storage capacitors/electrodes,common electrodes, conductive wires/pathways, etc., of the displaycircuitry in the display system, and that may also be configured tooperate as circuit elements of the touch sensing circuitry. In this way,for example, in some embodiments a display with integrated touch sensingcapability may be manufactured using fewer parts and/or processingsteps, and the display itself may be thinner, brighter, and require lesspower.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C illustrate an example mobile telephone, an example digitalmedia player, and an example personal computer that each include anexample integrated touch screen according to embodiments of thedisclosure.

FIGS. 1D-G illustrate an example integrated touch screen systemincluding a touch screen according to embodiments of the disclosure.

FIG. 2 is a block diagram of an example computing system thatillustrates one implementation of an example integrated touch screenaccording to embodiments of the disclosure.

FIG. 3 is a more detailed view of the touch screen of FIG. 2 showing anexample configuration of drive lines and sense lines according toembodiments of the disclosure.

FIG. 4 illustrates an example configuration in which touch sensingcircuitry includes common electrodes (Vcom) according to embodiments ofthe disclosure.

FIG. 5 illustrates an example configuration of conductive linesaccording to embodiments of the disclosure.

FIGS. 6-8 illustrate plan and side views showing more detail of exampledisplay pixels according to embodiments of the disclosure.

FIG. 9 is a partial circuit diagram of an example touch screen includinga plurality of sub-pixels according to embodiments of the disclosure.

FIGS. 10-12B illustrate an example touch sensing operation according toembodiments of the disclosure.

FIGS. 13A-B show another example configuration of multi-function displaypixels grouped into regions that function as touch sensing circuitryduring a touch phase of a touch screen according to embodiments of thedisclosure.

FIGS. 14A-16C illustrate another example configuration of multi-functioncircuit elements of display pixels according to embodiments of thedisclosure.

FIGS. 17-20 illustrate example display pixels in different stages ofmanufacture according to embodiments of the disclosure.

FIG. 21A illustrates an example layout of display pixels for one exampletouch pixel according to embodiments of the disclosure.

FIG. 21B is a magnified view of a portion of FIG. 21A illustrating anexample drive tunnel according to embodiments of the disclosure.

FIGS. 22-1 and 22-2 illustrate an example touch pixel layout that caninclude example touch pixels such as those shown in FIG. 21A.

FIG. 23 is a side view of an example touch screen including a highresistance (R) shield according to embodiments of the disclosure.

FIG. 24 is a partial top view of another example integrated touch screenin accordance with embodiments of the disclosure.

DETAILED DESCRIPTION

In the following description of example embodiments, reference is madeto the accompanying drawings which form a part hereof, and in which itis shown by way of illustration specific embodiments in whichembodiments of the disclosure can be practiced. It is to be understoodthat other embodiments can be used and structural changes can be madewithout departing from the scope of the embodiments of this disclosure.

The following description includes examples in which touch sensingcircuitry can be integrated into the display pixel stackup (i.e., thestacked material layers forming the display pixels) of a display, suchas an LCD display. While embodiments herein are described in referenceto LCD displays, it is understood that alternative displays may beutilized instead of the LCD display, such as generally any electricallyimageable layer containing an electrically imageable material. Theelectrically imageable material can be light emitting or lightmodulating. Light emitting materials can be inorganic or organic innature. Suitable materials can include organic light emitting diodes(OLED) or polymeric light emitting diodes (PLED). The light modulatingmaterial can be reflective or transmissive. Light modulating materialscan include, without limitation, electrochemical materials,electrophoretic materials such as Gyricon particles, electrochromicmaterials, or liquid crystal materials. Liquid crystal materials can be,without limitation, twisted nematic (TN), super-twisted nematic (STN),ferroelectric, magnetic, or chiral nematic liquid crystals. Othersuitable materials can include thermochromic materials, chargedparticles, and magnetic particles. Touch sensing circuitry can include,for example, touch signal lines, such as drive lines and sense lines,grounding regions, and other circuitry. Display pixel stackups aretypically manufactured by processes including depositing, masking,etching, doping, etc., of materials such as conductive materials (e.g.,metal, substantially transparent conductors), semiconductive materials(e.g., polycrystalline silicon (Poly-Si)), and dielectric materials(e.g., SiO2, organic materials, SiNx). Various structures formed withina display pixel stackup can be designed to operate as circuitry of thedisplay system to generate an image on the display. In other words, someof the stackup structures can be circuit elements of the displaycircuitry. Some embodiments of an integrated touch screen can includemulti-function circuit elements that can form part of the displaycircuitry of the display system, and can also form part of the touchsensing circuitry of a touch sensing system that senses one or moretouches on or near the display. The multi-function circuit elements canbe, for example, capacitors in display pixels of an LCD that can beconfigured to operate as storage capacitors/electrodes, commonelectrodes, conductive wires/pathways, etc., of the display circuitry inthe display system, and that may also be configured to operate ascircuit elements of the touch sensing circuitry. In this way, forexample, in some embodiments a display with integrated touch sensingcapability may be manufactured using fewer parts and/or processingsteps, and the display itself may be thinner, brighter, and require lesspower.

Example embodiments may be described herein with reference to aCartesian coordinate system in which the x-direction and the y-directioncan be equated to the horizontal direction and the vertical direction,respectively. However, one skilled in the art will understand thatreference to a particular coordinate system is simply for the purpose ofclarity, and does not limit the direction of the structures to aparticular direction or a particular coordinate system. Furthermore,although specific materials and types of materials may be included inthe descriptions of example embodiments, one skilled in the art willunderstand that other materials that achieve the same function can beused. For example, it should be understood that a “metal layer” asdescribed in the examples below can be a layer of any electricallyconductive material.

In some example embodiments, an LCD display with integrated touchsensing functionality may include a matrix of voltage data lines toaddress multi-function circuit elements of the display pixels to displayan image during a display phase, and to address the multi-functioncircuit elements of the display to sense touch during a touch sensingphase. Thus, in some embodiments, the multi-function circuit elementsmay operate as part of the display system during the display phase, andmay operate as part of the touch sensing system during the touch sensingphase. For example, in some embodiments, some of the voltage lines maybe driven with a first drive signal to drive the drive regions of thetouch screen during the touch sensing phase. In addition, one or more ofthe voltage lines may be driven with a second drive signal that is 180degrees out of sync with respect to the first drive signal used to drivethe drive regions of the touch screen. These out of sync voltage linesmay be used to reduce the static capacitance of the touch screens.

Some of the potential advantages of various embodiments of thedisclosure, such as thinness, brightness, and power efficiency, may beparticularly useful for portable devices, though use of embodiments ofthe disclosure is not limited to portable devices. FIGS. 1A-1C showexample systems in which an integrated touch screen according toembodiments of the disclosure may be implemented. FIG. 1A illustrates anexample mobile telephone 136 that includes an integrated touch screen124. FIG. 1B illustrates an example digital media player 140 thatincludes an integrated touch screen 126. FIG. 1C illustrates an examplepersonal computer 144 that includes an integrated touch screen 128.

FIGS. 1D-G illustrate an example integrated touch screen system 150,including an example integrated touch screen 153, according toembodiments of the disclosure. Referring to FIG. 1D, touch screen 153includes display pixels 155 that include multi-function circuitelements. FIG. 1D shows a magnified view of one display pixel 155, whichincludes multi-function circuit elements 157, 159, and 161 that canoperate as part of a display system controlled by a display systemcontroller 170 and can operate as part of the touch sensing circuitry ofa touch sensing system controlled by a touch sensing system controller180. Display pixel 155 also includes a multi-function circuit element163 that can operate as part the display circuitry of the displaysystem, the touch sensing system, and a power system controlled by apower system controller 190. Display pixel 155 also includes asingle-function, display circuit element 165 that in some embodimentscan operate as part of the display circuitry only, and asingle-function, touch sensing circuit element 167 that in someembodiments can operate as part of the touch sensing circuitry only.

FIGS. 1E-G illustrate an example operation of touch screen system 150,including different phases of operation. FIG. 1E shows an exampleoperation during a display phase, in which circuit elements of displaypixel 155 can operate to display an image on touch screen 153. Operationduring the display phase can include, for example, actively configuringdisplay pixel 155 into a display configuration by, for example,electrically separating or disconnecting touch sensing circuit element167 from circuit elements of the display circuitry with switches 169a-e. Actively configuring circuit elements of a display pixel to operateas part of the circuitry of a particular system of an integrated touchscreen can include, for example, switching connections between lines ofdifferent systems, turning circuit elements on/off, changing voltagelevels in voltage lines, changing signals, such as control signals, etc.Active configuration can occur during the operation of the touch screenand can be based at least in part on the static configuration, i.e., thestructural configuration, of the touch screen. Structural configurationcan include, for example, the size, shape, placement, materialcomposition, etc., of structures in the stackups of the display pixels,such as the number and placement of conductive pathways in the displaypixel stackups, permanent connections such as conductor-filled viasconnecting contact points of two conductive layers, permanent breakssuch as an portion of a conductive pathway in which the conductivematerial has been removed in the design, etc.

Display system controller 170 can transmit control signals 171, 173, and175 through multi-function circuit elements 159 and 163, and displaysystem circuit element 165, respectively, to cause multi-functioncircuit elements 157 and 161 of display pixels 150 to display an imageon touch screen 153. In some embodiments, control signals 171, 173, and175 can be, for example, a gate signal, a Vcom signal, and a datasignal.

FIG. 1F shows an example operation during a touch sensing phase, inwhich circuit elements of display pixel 155 can operate to sense touch,including actively configuring the display pixel for touch sensing by,for example, electrically connecting touch sensing circuit element 167with switches 169 b and 169 c, and electrically disconnecting displaysystem circuit element 165 with switches 169 a and 169 d. Touch sensingsystem controller 180 can transmit a control signal 181 and can receiveinformation signals 183 and 185. In some embodiments, control signal 181can be, for example, a drive signal for capacitive sensing, a drivesignal for optical sensing, etc. In some embodiments, information signal183 can be, for example, a sense signal for capacitive, optical, etc.sensing, and information signal 185 can be, for example, a feedbacksignal of the touch sensing system.

FIG. 1G shows an example operation during a power system phase, in whichmulti-function circuit element 163 of display pixel 155 can beelectrically disconnected from both the display system and the touchsensing system with switches 169 c, 169 d, and 169 e. Power systemcontroller 190 can transmit a signal 192 through multi-function circuitelement 163. Signal 192 can be, for example, a signal indicating arecharge state of the power system, a power supply voltage, etc.

In some embodiments of the disclosure, the touch sensing system can bebased on capacitance. By detecting changes in capacitance at each of thetouch pixels and noting the position of the touch pixels, the touchsensing system can recognize multiple objects, and determine thelocation, pressure, direction, speed and/or acceleration of the objectsas they are moved across the touch screen.

By way of example, some embodiments of an integrated touch sensingsystem may be based on self capacitance and some embodiments may bebased on mutual capacitance. In a self capacitance based touch system,each of the touch pixels can be formed by an individual electrode thatforms a self-capacitance to ground. As an object approaches the touchpixel, an additional capacitance to ground can be formed between theobject and the touch pixel. The additional capacitance to ground canresult in a net increase in the self-capacitance seen by the touchpixel. This increase in self-capacitance can be detected and measured bythe touch sensing system to determine the positions of multiple objectswhen they touch the touch screen. In a mutual capacitance based touchsystem, the touch sensing system can include, for example, drive regionsand sense regions, such as drive lines and sense lines. In one examplecase, drive lines can be formed in rows while sense lines can be formedin columns (e.g., orthogonal). The touch pixels can be provided at theintersections of the rows and columns. During operation, the rows can bestimulated with an AC waveform and a mutual capacitance can be formedbetween the row and the column of the touch pixel. As an objectapproaches the touch pixel, some of the charge being coupled between therow and column of the touch pixel can instead be coupled onto theobject. This reduction in charge coupling across the touch pixel canresult in a net decrease in the mutual capacitance between the row andthe column and a reduction in the AC waveform being coupled across thetouch pixel. This reduction in the charge-coupled AC waveform can bedetected and measured by the touch sensing system to determine thepositions of multiple objects when they touch the touch screen. In someembodiments, an integrated touch screen can be multi-touch, singletouch, projection scan, full-imaging multi-touch, or any capacitivetouch.

FIG. 2 is a block diagram of an example computing system 200 thatillustrates one implementation of an example integrated touch screen 220according to embodiments of the disclosure. Computing system 200 couldbe included in, for example, mobile telephone 136, digital media player140, personal computer 144, or any mobile or non-mobile computing devicethat includes a touch screen. Computing system 200 can include a touchsensing system including one or more touch processors 202, peripherals204, a touch controller 206, and touch sensing circuitry (described inmore detail below). Peripherals 204 can include, but are not limited to,random access memory (RAM) or other types of memory or storage, watchdogtimers and the like. Touch controller 206 can include, but is notlimited to, one or more sense channels 208, channel scan logic 210 anddriver logic 214. Channel scan logic 210 can access RAM 212,autonomously read data from the sense channels and provide control forthe sense channels. In addition, channel scan logic 210 can controldriver logic 214 to generate stimulation signals 216 at variousfrequencies and phases that can be selectively applied to drive regionsof the touch sensing circuitry of touch screen 220, as described in moredetail below. In some embodiments, touch controller 206, touch processor202 and peripherals 204 can be integrated into a single applicationspecific integrated circuit (ASIC).

Computing system 200 can also include a host processor 228 for receivingoutputs from touch processor 202 and performing actions based on theoutputs. For example, host processor 228 can be connected to programstorage 232 and a display controller, such as an LCD driver 234. Hostprocessor 228 can use LCD driver 234 to generate an image on touchscreen 220, such as an image of a user interface (UI), and can use touchprocessor 202 and touch controller 206 to detect a touch on or neartouch screen 220, such a touch input to the displayed UI. The touchinput can be used by computer programs stored in program storage 232 toperform actions that can include, but are not limited to, moving anobject such as a cursor or pointer, scrolling or panning, adjustingcontrol settings, opening a file or document, viewing a menu, making aselection, executing instructions, operating a peripheral deviceconnected to the host device, answering a telephone call, placing atelephone call, terminating a telephone call, changing the volume oraudio settings, storing information related to telephone communicationssuch as addresses, frequently dialed numbers, received calls, missedcalls, logging onto a computer or a computer network, permittingauthorized individuals access to restricted areas of the computer orcomputer network, loading a user profile associated with a user'spreferred arrangement of the computer desktop, permitting access to webcontent, launching a particular program, encrypting or decoding amessage, and/or the like. Host processor 228 can also perform additionalfunctions that may not be related to touch processing.

Touch screen 220 can include touch sensing circuitry that can include acapacitive sensing medium having a plurality of drive lines 222 and aplurality of sense lines 223. It should be noted that the term “lines”is a sometimes used herein to mean simply conductive pathways, as oneskilled in the art will readily understand, and is not limited tostructures that are strictly linear, but includes pathways that changedirection, and includes pathways of different size, shape, materials,etc. Drive lines 222 can be driven by stimulation signals 216 fromdriver logic 214 through a drive interface 224, and resulting sensesignals 217 generated in sense lines 223 can be transmitted through asense interface 225 to sense channels 208 (also referred to as an eventdetection and demodulation circuit) in touch controller 206. In thisway, drive lines and sense lines can be part of the touch sensingcircuitry that can interact to form capacitive sensing nodes, which canbe thought of as touch picture elements (touch pixels), such as touchpixels 226 and 227. This way of understanding can be particularly usefulwhen touch screen 220 is viewed as capturing an “image” of touch. Inother words, after touch controller 206 has determined whether a touchhas been detected at each touch pixel in the touch screen, the patternof touch pixels in the touch screen at which a touch occurred can bethought of as an “image” of touch (e.g. a pattern of fingers touchingthe touch screen).

FIG. 3 is a more detailed view of touch screen 220 showing an exampleconfiguration of drive lines 222 and sense lines 223 according toembodiments of the disclosure. As shown in FIG. 3, each drive line 222can be formed of one or more drive line segments 301 that can beelectrically connected by drive line links 303 at connections 305. Driveline links 303 are not electrically connected to sense lines 223,rather, the drive line links can bypass the sense lines through bypasses307. Drive lines 222 and sense lines 223 can interact capacitively toform touch pixels such as touch pixels 226 and 227. Drive lines 222(i.e., drive line segments 301 and corresponding drive line links 303)and sense lines 223 can be formed of electrical circuit elements intouch screen 220. In the example configuration of FIG. 3, each of touchpixels 226 and 227 can includes portion of one drive line segment 301, aportion of a sense line 223, and a portion of another drive line segment301. For example, touch pixel 226 can include a right-half portion 309of a drive line segment on one side of a portion 311 of a sense line,and a left-half portion 313 of a drive line segment on the opposite sideof portion 311 of the sense line.

The circuit elements can include, for example, structures that can existin conventional LCD displays, as described above. It is noted thatcircuit elements are not limited to whole circuit components, such awhole capacitor, a whole transistor, etc., but can include portions ofcircuitry, such as only one of the two plates of a parallel platecapacitor. FIG. 4 illustrates an example configuration in which commonelectrodes (Vcom) can form portions of the touch sensing circuitry of atouch sensing system according to embodiments of the disclosure. Commonelectrodes are circuit elements of the display system circuitry in thestackup (i.e., the stacked material layers forming the display pixels)of the display pixels of some types of conventional LCD displays, e.g.,fringe field switching (FFS) displays, that can operate as part of thedisplay system to display an image. In the example shown in FIG. 4, acommon electrode (Vcom) 401 (e.g., element 161 of FIG. 1D) can serve asa multi-function circuit element that can operate as display circuitryof the display system of touch screen 220 and can also operate as touchsensing circuitry of the touch sensing system. In this example, commonelectrode 401 can operate as a common electrode of the display circuitryof the touch screen, and can also operate together when grouped withother common electrodes as touch sensing circuitry of the touch screen.For example, a group of common electrodes 401 can operate together as acapacitive part of a drive line or a sense line of the touch sensingcircuitry during the touch sensing phase. Other circuit elements oftouch screen 220 can form part of the touch sensing circuitry by, forexample, electrically connecting together common electrodes 401 of aregion, switching electrical connections, etc. In general, each of thetouch sensing circuit elements may be either a multi-function circuitelement that can form part of the touch sensing circuitry and canperform one or more other functions, such as forming part of the displaycircuitry, or may be a single-function circuit element that can operateas touch sensing circuitry only. Similarly, each of the display circuitelements may be either a multi-function circuit element that can operateas display circuitry and perform one or more other functions, such asoperating as touch sensing circuitry, or may be a single-functioncircuit element that can operate as display circuitry only. Therefore,in some embodiments, some of the circuit elements in the display pixelstackups can be multi-function circuit elements and other circuitelements may be single-function circuit elements. In other embodiments,all of the circuit elements of the display pixel stackups may besingle-function circuit elements.

In addition, although example embodiments herein may describe thedisplay circuitry as operating during a display phase, and describe thetouch sensing circuitry as operating during a touch sensing phase, itshould be understood that a display phase and a touch sensing phase maybe operated at the same time, e.g., partially or completely overlap, orthe display phase and touch phase may operate at different times. Also,although example embodiments herein describe certain circuit elements asbeing multi-function and other circuit elements as beingsingle-function, it should be understood that the circuit elements arenot limited to the particular functionality in other embodiments. Inother words, a circuit element that is described in one exampleembodiment herein as a single-function circuit element may be configuredas a multi-function circuit element in other embodiments, and viceversa.

For example, FIG. 4 shows common electrodes 401 grouped together to formdrive region segments 403 and sense regions 405 that generallycorrespond to drive line segments 301 and sense lines 223, respectively.Grouping multi-function circuit elements of display pixels into a regioncan mean operating the multi-function circuit elements of the displaypixels together to perform a common function of the region. Groupinginto functional regions may be accomplished through one or a combinationof approaches, for example, the structural configuration of the system(e.g., physical breaks and bypasses, voltage line configurations), theoperational configuration of the system (e.g., switching circuitelements on/off, changing voltage levels and/or signals on voltagelines), etc.

In some embodiments, grouping of circuit elements can be implemented asa layout of display pixels, each display pixel being selected from a setof a limited number of display pixel configurations. In someembodiments, a particular function of touch sensing circuitry may beserved by a particular type of display pixel having a configuration thatcan perform the function. For example, one embodiment described belowwith reference to FIGS. 17-22 can include display pixels of a type thatcan connect together one or more adjacent pixels in a connection layerof the stackup, display pixels of a type that can provide a contact toanother layer of the stackup, and display pixels of a type that canconnect together one or more adjacent pixels in the other layer.

In some embodiments, regions may be reconfigurable, for example, toallow pixels to be grouped into regions of different sizes, shapes, etc.For example, some embodiments may include programmable switching arraysto allow reconfigurable switching schemes to group display pixels intoregions of different sizes depending on, for example, variations inenvironmental noise, size and/or distance of the object to be sensedfrom the touch screen, etc. Other aspects of configurations that canallow grouping may not be reconfigurable, for example, physical breaksin lines in the stackup of a display pixel are not reconfigurable.However, a touch screen configuration including physical breaks, forexample, may still allow reconfigurable grouping of display pixels intodifferently sized, shaped, etc., regions by including other circuitelements that are reconfigurable, such as programmable switches, signalgenerators, etc.

Multi-function circuit elements of display pixels of the touch screencan operate in both the display phase and the touch phase. For example,during a touch phase, common electrodes 401 can be grouped together toform touch signal lines, such as drive regions and sense regions. Insome embodiments circuit elements can be grouped to form a continuoustouch signal line of one type and a segmented touch signal line ofanother type. For example, FIG. 4 shows one example embodiment in whichdrive region segments 403 and sense regions 405 correspond to drive linesegments 301 and sense lines 223 of touch screen 220. Otherconfigurations are possible in other embodiments, for example, commonelectrodes 401 could be grouped together such that drive lines are eachformed of a continuous drive region and sense lines are each formed of aplurality of sense region segments linked together through connectionsthat bypass a drive region. More details of operations in an exampledisplay phase and an example touch phase are described below inreference to FIGS. 11A-B.

The drive regions in the example of FIG. 3 are shown in FIG. 4 asrectangular regions including a plurality of common electrodes ofdisplay pixels, and the sense regions of FIG. 3 are shown in FIG. 4 asrectangular regions including a plurality of common electrodes ofdisplay pixels extending the vertical length of the LCD. In someembodiments, a touch pixel of the configuration of FIG. 4 can include,for example, a 64×64 area of display pixels. However, the drive andsense regions are not limited to the shapes, orientations, and positionsshown, but can include any suitable configurations according toembodiments of the disclosure. It is to be understood that the displaypixels used to form the touch pixels are not limited to those describedabove, but can be any suitable size or shape to permit touchcapabilities according to embodiments of the disclosure.

FIG. 5 illustrates an example configuration of conductive lines that canbe used to group common electrodes 401 into the regions shown in FIG. 4and to link drive region segments to form drive lines according toembodiments of the disclosure. Some embodiments can include otherregions, such as a grounding region between drive lines and/or betweendrive lines and sense lines, as illustrated in the example embodimentshown in FIG. 13.

FIG. 5 shows a plurality of xVcom lines 501 along the x-direction and aplurality of yVcom lines 503 along the y-direction. In this embodiment,each row of common electrodes 401 can have a corresponding xVcom line501 and each column of common electrodes 401 can have a correspondingyVcom line 503. FIG. 5 further shows a plurality of drive regionsegments 403 (illustrated by dashed lines), where each drive regionsegment 403 can be formed as a group of common electrodes 401 connectedtogether through x-y-com connections 505, which connect each commonelectrode to an xVcom line 501 and a yVcom line 503 in the drive regionsegment, as described in more detail below. The yVcom lines 503 runningthrough the drive region segments 403, such as yVcom line 503 a, caninclude break 509 that provide electrical separation of each driveregion segment from other drive region segments (e.g., segments aboveand below a given drive region segment). Breaks 509 can provide ay-disconnection (an electrical disconnection in the y-direction).

Drive lines 511 can each be formed by a plurality of drive regionsegments 403 which can be formed by the common electrodes 401 and theirinterconnecting conducting lines xVcom. Specifically, drive lines 511can be formed by connecting drive region segments 403 across senseregions 405 using xVcom lines 501. As shown in FIG. 5, a first driveline 511 a can be formed by the top row of drive region segments 403,and a next drive line 511 b can be formed by the next row of driveregion segments 403. The xVcom lines are conductive pathways that bypassthe yVcom lines in the sense region 405 using bypasses 513, as describedin more detail below.

FIG. 5 further shows a plurality of sense regions 405 (illustrated bydashed lines). Each sense region 405 can be formed as a group of commonelectrodes 401 connected together through y-com connections 507, whichcan connect each common electrode of the sense region 405 to one of theyVcom lines 503. Additional connections (see, for example, FIG. 10) canconnect together the yVcom lines of each sense region 405. For example,the additional connections can include switches in the border of touchscreen 220 that can connect together the yVcom lines of each senseregion during the touch phase of operation. The yVcom lines 503 runningthrough the sense regions 405, such as yVcom line 503 b, canelectrically connect all of the common electrodes 401 in they-direction, therefore, the yVcom lines of the sense regions do notinclude breaks. In this way, for example, a sense region can be formedby a plurality of vertical common voltage lines yVcom connected to oneanother and to circuit elements of corresponding display pixels, therebyforming a sense line 512 consisting of electrically connected circuitelements of display pixels in the sense region. In the example senseregion shown in FIG. 5, the vertical common voltage lines yVcom can beunconnected from and can cross over (at 513) the horizontal commonvoltage lines xVcom to form a structure for capacitive touch sensing.This cross over yVcom and xVcom may also form an additional parasiticcapacitance between the sense and drive regions.

Each common electrode 401 can correspond to a display pixel of touchscreen 220, such as display pixels 515 and 517. During a display phase,common electrodes 401 an operate along with other display pixelcomponents as display circuitry of the display system of touch screen220 to display an image on the touch screen. During a touch phase,groups of common electrodes 401 can operate as touch sensing circuitryof the touch sensing system of touch screen 220 to detect one or moretouches on or near the touch screen.

In operation during a touch phase, the horizontal common voltage linesxVcom 501 can transmit stimulation signals to stimulate the drive lines511 and form electric fields between the stimulated drive lines andsense lines 512 to create touch pixels, such as touch pixel 226 in FIG.3. When an object such as a finger approaches or touches a touch pixel,the object can affect the electric fields extending between the driveline 511 and the sense line 512, thereby reducing the amount of chargecapacitively coupled to the sense line. This reduction in charge can besensed by the sense channel and stored in memory along with similarinformation of other touch pixels to create an “image” of touch.

In some embodiments, the drive lines and/or sense lines can be formed ofother structures including, for example other structures alreadyexisting in typical LCD displays (e.g., other electrodes, conductiveand/or semiconductive layers, metal lines that would also function ascircuit elements in a typical LCD display, for example, carry signals,store voltages, etc.), other structures formed in an LCD stackup thatare not typical LCD stackup structures (e.g., other metal lines, plates,whose function would be substantially for the touch sensing system ofthe touch screen), and structures formed outside of the LCD stackup(e.g., such as external substantially transparent conductive plates,wires, and other structures). For example, part of the touch sensingsystem can include structures similar to known touch panel overlays.Forming a touch sensing system in part or in whole using structures thatalready exist in displays can potentially increase the image quality,brightness, etc. of the touch screen by reducing the amount of structurededicated primarily to touch sensing that would typically overlay thedisplay.

In some embodiments, display pixels can be grouped into regions betweena drive region and a sense region and/or between two drive regions, forexample, and these regions may be connected to ground or a virtualground to form a grounded region in order to further minimize theinterference between drive regions and/or between the drive regions andthe sense regions. FIGS. 13A-B show an example layout of regionsaccording to embodiments of the disclosure including a grounding regionbetween drive regions and between drive regions and sense regions. Inother embodiments, the vertical common voltage line breaks can beomitted and the lines shared in their entirety among the drive regions.

As seen in FIG. 5, display pixel 515 can be grouped into a sense region405, and display pixel 517 can be grouped into a drive region segment403. FIGS. 6-8 illustrate plan and side views showing more detail ofdisplay pixels 515 and 517 in “Box A” of FIG. 5, and show one exampleconfiguration including example breaks/bypasses that arein-plane/in-layer and example breaks/bypasses that areout-of-plane/out-of-layer according to embodiments of the disclosure.

FIG. 6 is a magnified view of “Box A” in FIG. 5, showing more detail ofdisplay pixels 515 and 517 and other structures of touch screen 220according to embodiments of the present disclosure. Display pixels 515and 517 can each include a common electrode 401 and three display pixelelectrodes 601, one each for a red (R) sub-pixel, a green (G) sub-pixel,and a blue (B) sub-pixel corresponding to an R data line 603, a G dataline 605, and a B data line 607 that provide color data to thesub-pixels when the sub-pixels' transistors 609 are switched on by avoltage applied across a gate line 611 during the display phase of thetouch screen.

In some embodiments, other types of display pixels can be used, such asmonochrome (e.g., black and white) display pixels, display pixelsincluding more than or fewer than three sub-pixels, display pixels thatoperated in a non-visible spectrum, such as infrared, etc. Differentembodiments can include display pixels having a different size, shape,optical properties. The display pixels of some embodiments may be ofdifferent sizes, shapes, optical properties, etc., with respect to eachother, and the different types of display pixels utilized in a touchscreen may provide different functionalities in some embodiments.

FIG. 6 also illustrates that yVcom line 503 running through displaypixel 517 has break 509 separating display pixel 517 (and display pixel517's drive region segment 403, see FIG. 5) from the adjacent driveregion segment. Break 509 is an example of an in-plane break that is anelectrical open between conductive pathways running in substantially thesame plane, in this case the x-y plane in which yVcom line 503 runs.Likewise, break 509 is an example of an in-layer break that is anelectrical open between conductive pathways running in the same layer,in this case the second metal layer, as described below. While manyin-layer breaks may also be in-plane breaks, this is not necessarily thecase. For example, a break in a conductive pathway of a material layerin a stackup could occur at a location at which the layer is formed atdifferent stackup heights (i.e., different planes), and thus a break atsuch a location would be an in-layer, out-of-plane break, rather than anin-layer, in-plane break.

On the other hand, yVcom line 503 running through display pixel 515 ofsense region 405 does not include a break, so that display pixel 515 maybe electrically connected to other display pixels of sense region 405 inthe y-direction, i.e., the display pixels in the sense region arey-connected.

An xVcom line 501 runs in the x-direction through display pixels 515 and517. The xVcom line 501 lies behind R, G, and B data lines 603, 605, and607, respectively, as shown in the magnified view of the xVcom behindthe R data line 603 at the upper left corner of display pixel 515.Connections between the xVcom and yVcom lines and the common electrodes401 of display pixels 515 and 517 are shown in more detail in explodedviews in FIG. 6, which also show that xVcom line 501 lies behind yVcomline 503, and yVcom line 503 lies behind common electrode 401. For thesense region's display pixel 515, the exploded view of y-com connection507 of display pixel 515 shows that the y-com connection is a conductiveline 613 (e.g., a via filled with a conductive material) between yVcomline 503 and common electrode 401 of the display pixel, and shows thatthere is no connection, i.e., a bypass 513, between xVcom line 501 andyVcom line 503 (and therefore, no connection between the xVcom line andthe common electrode). As a result of bypass 513, display pixel 515 canbe x-disconnected, or isolated in the x-direction, that is, disconnectedor isolated from adjacent display pixels along the x-direction. In thisexample embodiment, the additional connections of the sense region'syVcom lines 503, such as the border switches described above,electrically connect the common electrode 401 of display pixel 515 tothe common electrode of the adjacent sense region display pixel to theleft of display pixel 515, therefore bypass 513 “right-disconnects”display pixel 515 from the adjacent drive region display pixel 517 tothe right of display pixel 515 (in other words, display pixel 515 can bex-disconnected from display pixels in the positive x-direction, i.e.,positive x-disconnected).

Bypass 513 is an example of an out-of-plane bypass that can be anelectrical open between conductive pathways running in substantiallydifferent planes; in this case the x-y plane in which yVcom line 503runs can be different than the x-y plane in which xVcom line 501 runs.Likewise, bypass 513 is an example of an out-of-layer bypass that can bean electrical open between conductive pathways running in differentlayers, in this case the second metal layer of yVcom 503 and the firstmetal layer of xVcom 501, as described below. This configuration,including the yVcom-to-common electrode connection, yVcom-to-yVcomconnections in the touch screen border (for yVcom lines of the samesense region, as described above), and bypasses between the xVcom andyVcom lines, is one example of grouping together circuit elements of adisplay in a sense region to form a sense line for touch sensing, andbypassing the sense line with an xVcom line that links together driveregion segments that are separated from each other by the sense regionto form a drive line for touch sensing.

For the drive region segment's display pixel 517, the exploded view ofx-y-com connection 505 of display pixel 517 shows that the x-y-comconnection can include a conductive line 615 connecting the xVcom lineto the yVcom line, and one of conductive lines 613 connecting the yVcomline to the common electrode. Thus, the common electrodes of eachdisplay pixel in a drive region segment can be electrically connectedtogether because each display pixel can be connected to the sameconductive grid of vertical lines (yVcom), i.e., y-connected, andhorizontal lines (xVcom), i.e., x-connected. In this exampleconfiguration, the common electrodes, vertical lines, and horizontallines can be oriented in different substantially coplanar planes andconnected together through two sets of connections, one set connectingthe vertical and horizontal lines, and the other set connecting thevertical lines and the common electrodes. This configuration, includingthe breaks in the vertical lines, is one example of grouping togethercircuit elements of a display in a drive region segment to form touchsensing circuitry of a drive line that can be linked to other drive linesegments through drive line links that bypass intervening sense lines.

FIGS. 7-8 are cross section views illustrating a portion of the displaypixel 515 stackup and a portion of the display pixel 517 stackup,respectively. FIG. 7 shows a view of a cross section of display pixel515 taken along the arrowed line from 7-7′ of FIG. 6. FIG. 7 includesgate line 611 and xVcom line 501 formed in a first metal layer (M1), Bdata line 607, a drain 701, and yVcom line 503 formed in a second metallayer (M2). The figure also includes common electrode 401 and displaypixel electrode 601 formed of a transparent conductor, such as ITO.Common electrode 401 can be electrically connected to yVcom line 503through a via in a dielectric layer 707 a that can be filled with aconductive material, conductive via 703, which is one example ofconductive line 613 of FIG. 6. FIG. 7 also shows bypass 513 (noconnection) between xVcom 501 and yVcom 503. In this regard, bypass 513can be regarded as the structure that separates xVcom 501 and yVcom 503,which can include a portion of dielectric layer 707 b. A gate insulatorlayer 705 may comprise a dielectric material, such as SiO2, SiNx, etc.The liquid crystal layer can be disposed above the pixel electrodesfollowed by color filters, and polarizers can be positioned on top andbottom of the stackup (not shown). The touch screen is viewed from thetop in relation to FIG. 7.

FIG. 8 shows a view of a cross section of display pixel 517 taken alongthe arrowed line from 8-8′ of FIG. 6. FIG. 8 is identical to FIG. 7except that a conductive via 801 in FIG. 8 replaces bypass 513 in FIG.7. Thus, xVcom 501 can be electrically connected to yVcom 503 in thedrive region segment display pixel 517. Thus, conductive line 615 inFIG. 6 can be a conductor-filled via in this example stackup.

Taken together, FIGS. 7-8 illustrate one example of how the use ofout-of-plane/out-of-layer breaks/bypasses according to embodiments ofthe disclosure may, in some embodiments, provide an efficient way tocreate a multi-function touch sensing LCD structure includingmulti-function circuit elements. In this case, in some embodimentsconnections/bypasses made between the conductive pathways in differentplanes/layers can allow for more options in the design of amulti-function configuration, and could potentially reduce the number ofadded structures, e.g., lines, that would otherwise need to be added toform bypasses in the same plane/layer. In this regard, y-disconnectionsand/or x-disconnections in some embodiments may be conveniently formedby simply forming conductive pathways in different planes/layers of adisplay pixel stackup, for example. Likewise, y-connections and/orx-connections in some embodiments may be conveniently formed usingconductive pathways between different planes/layers to connectconductive pathways in the different planes/layers. In particular, thismay allow existing LCD design to be more easily modified to addintegrated touch functionality according to embodiments of thedisclosure. In this regard, selective use of in-plane/in-layer andout-of-plane/out-of-layer breaks and bypasses may allow more of thestructures in existing LCD designs to be used as circuit elements in thetouch sensing system, and may reduce the number of changes needed toexisting manufacturing processes, such as masking, doping, depositing,etc.

Further details of an example touch screen and an example method ofoperating multi-function touch screen LCD circuit elements will bedescribed in reference to FIGS. 9-12B. FIG. 9 is a partial circuitdiagram of an example touch screen 900, including a plurality ofsub-pixels according to embodiments of the disclosure. As in exampleembodiments described above, the sub-pixels of touch screen 900 can beconfigured such that they are capable of multi-functionality as both LCDsub-pixels and touch sensor circuit elements. That is, the sub-pixelscan include circuit elements that can operate as part of the LCDcircuitry of the display pixels and that can also operate as circuitelements of touch sensing circuitry. In this way, touch screen 900 canoperate as an LCD with integrated touch sensing capability. FIG. 9 showsdetails of sub-pixels 901, 902, and 903 of touch screen 900. In thisexample embodiment, each sub-pixels can be a red (R), green (G) or blue(B) sub-pixel, with the combination of all three R, G and B sub-pixelsforming one color display pixel. Although this example embodimentincludes red, green, and blue sub-pixels, a sub-pixel may be based onother colors of light or other wavelengths of electromagnetic radiation(e.g., infrared) or may be based on a monochromatic configuration.

Sub-pixel 902 can include a thin film transistor (TFT) 955 with a gate955 a, a source 955 b, and a drain 955 c. Sub-pixel 902 can also includea common electrode (Vcom) 957 b that can be, for example, a continuousplate of substantially conductive material shared among sub-pixels 901,902, and 903, such as common electrode 401 shown in FIG. 6. Sub-pixel902 can also include a pixel electrode 957 a that can operate withcommon electrode 957 b as part of the display system circuitry. Pixelelectrode 957 a can, for example, be the pixel electrode 601 shown inFIGS. 6-8. Touch screen 900 can operate as an FFS display system inwhich the pixel electrode of each sub-pixel and the common electrodegenerate the fringe field applied to the liquid crystal of thesub-pixel, and can also form a storage capacitor of the sub-pixel.Sub-pixel 902 can include a storage capacitor 957 formed by pixelelectrode 957 a and common electrode 957 b. Sub-pixel 902 can alsoinclude a portion 917 a of a data line for green (G) color data, Gdataline 917, and a portion 913 b of a gate line 913. Gate 955 a can beconnected to gate line portion 913 b, and source 955 b is connected toGdata line portion 917 a. Pixel electrode 957 a can be connected todrain 955 c of TFT 955.

Sub-pixel 901 can include a thin film transistor (TFT) 905 with a gate905 a, a source 905 b, and a drain 905 c. Sub-pixel 901 can also includea pixel electrode 907 a that can operate with common electrode 957 b togenerate the fringe field for the sub-pixel and to form a storagecapacitor 907. Sub-pixel 901 can also include a portion 915 a of a dataline for red (R) color data, Rdata line 915, and a portion 913 a of gateline 913. Gate 905 a can be connected to gate line portion 913 a, andsource 905 b can be connected to Rdata line portion 915 a. Pixelelectrode 907 a can be connected to drain 905 c of TFT 905. Sub-pixels901 and 902 can include, for example, most or all of the structure ofconventional LCD sub-pixels.

Sub-pixel 903 can include a thin film transistor (TFT) 975 with a gate975 a, a source 975 b, and a drain 975 c. Sub-pixel 903 can also includea pixel electrode 977 a that can operate with common electrode 957 b togenerate the fringe field for the sub-pixel and to form a storagecapacitor 977. Sub-pixel 903 can also include a portion 919 a of a dataline for blue (B) color data, Bdata line 919, and a portion 913 c ofgate line 913. Gate 975 a can be connected to gate line portion 913 c,and source 975 b can be connected to Bdata line portion 919 a. Pixelelectrode 977 a can be connected to drain 975 c of TFT 975. Unlikesub-pixels 901 and 902, sub-pixel 903 can also include a portion 925 aof a common voltage line running in the y-direction, yVcom 925, and aconnection point 929. In other embodiments, the yVcom could run throughthe red sub-pixels or the green sub-pixels, instead of the bluesub-pixels. A connection, such as y-com connection 507 or x-y-comconnection 505 described above in reference to FIG. 6, can be made atconnection point 929 in order, for example, to connect common electrode957 b to yVcom 925 (which runs vertically through other display pixels),to connect common electrode 957 b to yVcom 925 and xVcom 921 (which runshorizontally through other pixels), etc. In this way, for example,common electrode 957 b can be connected with common electrodes of otherdisplay pixels to create regions of connected common electrodes.

One way to create separate regions is by forming breaks (opens) in thehorizontal and/or vertical common lines, as described above in someexample embodiments. For example, yVcom 925 can have an optional breakas shown in FIG. 9, which can allow sub-pixels above the break to beisolated from sub-pixels below the break, i.e., the sub-pixels can bebottom-disconnected. An x-disconnection can be created by forming ay-com connection instead of an x-y-com connection at connection point929, thus, disconnecting xVcom 921 from common electrode 957 b. In someembodiments, xVcom 921 may include breaks, which can allow sub-pixels tothe right of the break to be isolated from sub-pixels to the left of thebreak. Other configurations can allow display pixel circuit elements tobe grouped as described above with drive line segments linked togetherthrough bypasses of sense lines.

In this way, common electrodes of touch screen 900 can be groupedtogether to form a structure within the display pixels that can operateas part of the touch sensing circuitry of a touch sensing system. Forexample, the common electrodes can be configured to form drive regionsor sense regions, to form bypasses and links as described above for someembodiments, etc. In this regard, circuit elements such as the commonelectrodes, the xVcom lines, etc. can operate as multi-function circuitelements.

In general, touch screen 900 could be configured such that the commonelectrodes of all sub-pixels in the screen can be connected together,for example, through at least one vertical common voltage line withconnections to a plurality of horizontal common voltage lines. Anothertouch screen could be configured such that different groups ofsub-pixels can be connected together to form a plurality of separateregions of connected-together common electrodes.

A touch sensing operation according to embodiments of the disclosurewill be described with reference to FIGS. 10-12B. FIG. 10 shows partialcircuit diagrams of some of the touch sensing circuitry within displaypixels in a drive region 1001 and a sense region 1003 of an exampletouch screen according to embodiments of the disclosure. For the sake ofclarity, FIG. 10 includes circuit elements illustrated with dashed linesto signify some circuit elements operate primarily as part of thedisplay circuitry and not the touch sensing circuitry. In addition, atouch sensing operation is described primarily in terms of a singledrive display pixel 1001 a (e.g., a single display pixel of drive region1001) and a single sense display pixel 1003 a (e.g., a single displaypixel of sense region 1003). However, it is understood that other drivedisplay pixels in drive region 1001 can include the same touch sensingcircuitry as described below for drive display pixel 1001 a, and theother sense display pixels in sense region 1003 can include the sametouch sensing circuitry as described below for sense display pixel 1003a. Thus, the description of the operation of drive display pixel 1001 aand sense display pixel 1003 a can be considered as a description of theoperation of drive region 1001 and sense region 1003, respectively.

Referring to FIG. 10, drive region 1001 includes a plurality of drivedisplay pixels including drive display pixel 1001 a. Drive display pixel1001 a includes a TFT 1007, a gate line 1011, a data line 1013, an xVcomline portion 1015 and a yVcom line portion 1017, a pixel electrode 1019,and a common electrode 1023. FIG. 10 shows common electrode 1023connected to the common electrodes in other drive display pixels indrive region 1001 through xVcom line portions 1015 and yVcom lineportions 1017 to form a structure within the display pixels of driveregion 1001 that is used for touch sensing as described in more detailbelow. Sense region 1003 includes a plurality of sense display pixelsincluding sense display pixel 1003 a. Sense display pixel 1003 aincludes a TFT 1009, a gate line 1012, a data line 1014, a yVcom lineportion 1016, a pixel electrode 1021, and a common electrode 1025. FIG.10 shows common electrode 1025 connected to the common electrodes inother sense display pixels in sense region 1003 through yVcom lineportions 1016 that can be connected, for example, in a border region ofthe touch screen to form a structure within the display pixels of senseregion 1003 that is used for touch sensing as described in more detailbelow.

During a touch sensing phase, drive signals applied to xVcom lineportions 1015 generate an electrical field between the structure ofconnected common electrodes 1023 of drive region 1001 and the structureof connected common electrodes of 1025 of sense region 1003, which isconnected to a sense amplifier, such as a charge amplifier 1026.Electrical charge is injected into the structure of connected commonelectrodes of sense region 1003, and charge amplifier 1026 converts theinjections of charge into a voltage that can be measured. The amount ofcharge injected, and consequently the measured voltage, can depend onthe proximity of a touch object, such as a finger 1027, to the drive andsense regions. In this way, the measured voltage can provide anindication of touch on or near the touch screen.

FIG. 11A shows example signals applied through xVcom 1015 to the drivedisplay pixels of drive region 1001, including drive display pixel 1001a, during an example LCD or display phase and during an example touchphase. During the LCD phase, xVcom 1015 and yVcom 1017 can be drivenwith a square wave signal of 2.5V+/−2.5V, in order to perform LCDinversion. The LCD phase is 12 ms in duration.

In the touch phase, xVcom 1015 can be driven with an AC signal, such asa sinusoidal wave, a square wave, a triangular wave, etc. In the exampleshown in FIG. 11A, xVcom can be driven with 15 to 20 consecutivestimulation phases lasting 200 microseconds each while yVcom 1016 ismaintained at the virtual ground of charge amplifier 1026 as shown inFIG. 11B. The drive signals in this case can be square or sinusoidalsignals of 2.5V+/−2V each having the same frequency and a relative phaseof either 0 degrees or 180 degrees (corresponding to “+” and “−” in FIG.11A). The touch phase is 4 ms in duration.

FIG. 12A shows details of the operation of common electrode 1023 duringthe touch phase. In particular, because the capacitance of the storagecapacitor formed by common electrode 1023 and pixel electrode 1019 ismuch higher than other capacitances in the system (i.e., straycapacitances between various conductive structures and between thecommon electrode and finger 1027), almost all (approximately 90%) of theAC component of the 2.5V+/−2V sinusoidal drive signal that is applied tocommon electrode 1023 is also applied to pixel electrode 1019. Thus, thevoltage difference between common electrode 1023 and pixel electrode1019 can be kept small, and the liquid crystal will experience minimalelectric field changes due to the touch stimuli and maintain its chargestate as it was set during the LCD phase. The common electrodes 1023 and1025 can be charged typically to 0 or 5 volts DC (square wave2.5+/−2.0V) during display phase operation of the LCD. However, duringtouch mode, the common electrode in the drive region 1001 can be chargedto a DC voltage of 2.5 V with superimposed sinusoidal signal of 2 Vamplitude. Similarly, the common electrode in the sense region 1025 canbe kept at the virtual ground of charge amplifier 1026 at DC level of2.5 volts. During the touch phase, the sinusoidal signals on the commonelectrode 1023 in the drive region 1001 can be passed to commonelectrodes 1025 of sense region 1003. Due to high coupling between thecommon pixel electrodes in both drive and sense regions, 90% of thevoltage changes on the common electrode is transferred to correspondingpixel electrodes, hence minimizing the disturbance of image chargestored during the display phase while performing touch sensing. In thismanner, the common electrodes of the drive and sense regions can operateas circuit elements of the touch sensing circuitry by forming astructure for capacitance touch sensing without effecting the LCD image.

At the same time the common electrodes and pixel electrodes areconfigured to operate as circuit elements of the touch sensingcircuitry, the electrodes may continue to operate as a part of the LCDsystem. As shown in FIGS. 12A-B, while the voltages of the structures ofpixel electrode 1021 are each modulated at approximately +/−2V, therelative voltage between pixel electrode 1021 and common electrode 1025remains approximately at a constant value+/−0.1V. This relative voltageis the voltage that is seen by the liquid crystal of the display pixelfor the LCD operation, and its magnitude can determine the gray scalelevel of the image (for example in FIG. 12A, this relative voltage is2V). The 0.1V AC variance in the relative voltage during the touch(sense) phase should have an acceptably low affect on the LCD,particularly since the AC variance would typically have a frequency thatis higher than the response time for the liquid crystal. For example,the stimulation signal frequency, and hence the frequency of the ACvariance, would typically be more than 100 kHz. However, the responsetime for liquid crystal is typically less than 100 Hz. Therefore, thecommon and pixel electrodes' function as circuit elements in the touchsystem should not interfere with the LCD function.

Referring now to FIGS. 10, 11B, and 12B, an example operation of senseregion 1003 will now be described. FIG. 11B shows signals appliedthrough yVcom 1016 to the display pixels of the sense region, includingdisplay pixel 1003 a, during the LCD and touch phases described above.As with the drive region, yVcom 1016 is driven with a square wave signalof 2.5V+/−2.5V in order to perform LCD inversion during the LCD phase.During the touch phase, yVcom 1016 is connected to charge amplifier1026, which holds the voltage at or near a virtual ground of 2.5V.Consequently, pixel electrode 1021 is also held at 2.5V. As shown inFIG. 10, fringe electrical fields propagate from common electrode 1023to common electrode 1025. As described above, the fringe electricalfields are modulated at approximately +/−2V by the drive region. Whenthese fields are received by pixel electrode 1021, most of the signalgets transferred to common electrode 1025, because display pixel 1003 ahas the same or similar stray capacitances and storage capacitance asdisplay pixel 1001 a.

Because yVcom 1016 is connected to charge amplifier 1026, and is beingheld at virtual ground, charge injected into yVcom 1016 will produce anoutput voltage of the charge amplifier. This output voltage provides thetouch sense information for the touch sensing system. For example, whenfinger 1027 gets close to the fringe fields, it causes a disturbance inthe fields. This disturbance can be detected by the touch system as adisturbance in the output voltage of charge amplifier 1026.Approximately 90% of a fringe field impinging onto pixel electrode 1021that is connected to the drain of the TFT 1009 will be transferred tocharge amplifier 1026. 100% of the charge impinging onto commonelectrode 1025 that is connected directly to yVcom 1016 will betransferred to charge amplifier 1026. The ratio of charge impinging ontoeach electrode will depend on the LCD design. For non-IPS, nearly 100%of the finger affected charge may impinge on the common electrodebecause the patterned CF plate is nearest the finger. For an IPS-typedisplay the ratio may be closer to 50% because each part of theelectrode has approximately equal area (or ¼ vs. ¾) facing the finger.For some sub-types of IPS displays, the pixel electrodes are notcoplanar, and the majority of the upward facing area is devoted to thecommon electrode.

FIG. 13A shows another example configuration of multi-function displaypixels grouped into regions that function in the touch sensing systemduring a touch phase of a touch screen according to embodiments of thedisclosure. FIG. 13B shows a more detailed view of the touch screen withgrounding regions of FIG. 13A. As shown in FIGS. 13A-B, a region ofdisplay pixels can be formed between drive regions and sense regions,for example, and the region can be grounded to true ground to form adrive-sense grounding region 1301. FIGS. 13A-B also show a similargrouping of display pixels between two drive regions, which can belikewise grounded to form a drive-drive grounding region 1303. Groundingregions, and other regions, can be formed from, for example, aconnection structure, such as grid of conductive line portions. Forexample, FIGS. 13A-B show a grounding region connection grid 1304 ofhorizontal and vertical conductive pathways that include in-plane/layerbreaks (y-disconnections) 1305 and in-plane/layer breaks(x-disconnections) 1309. Lines linking the drive regions can bypass thegrounding regions and the sense regions with out-of-plane/layer bypasses1308. In the example configuration of FIGS. 13A-B, drive-sense groundingregion 1301 is electrically connected to drive-drive grounding regions1303 through connections 1310, and all of the grounding regions can begrounded to a single ground 1313 through a multiplexer 1311 at oneborder of the touch screen.

FIG. 13B shows grounding region connection grid 1304 can connect commonelectrodes of grounding regions 1301 and 1303 through connections 1310,while maintaining electrical separation from other regions with in-planebreaks 1305 (y-disconnections) and in-plane breaks 1309(x-disconnections). The common electrodes of the sense region can besimilarly connected with a grid. FIG. 13B also shows the commonelectrodes of drive regions can be formed of a different grid ofconductive lines connected by connections 1323 to form a drive regionconnection grid 1321. Horizontal lines of drive region connection gridcan bypass the grounding regions and the sense regions with a bypassingconductive pathway 1325 running through the grounding and sense regionsusing out-of-plane bypasses 1308, for example, to prevent electricalcontact between the drive region and the grounding and sense regions.Bypassing conductive pathway can be, for example, a drive tunneldescribed in more detail below. In the example configuration of FIGS.13A-B, grounding regions 1301 and 1303 are each two display pixels wide;however, the width of a grounding region is not limited to two displaypixels, but can be fewer or more display pixels in width. Likewise,although FIGS. 13A-B show drive-drive grounding regions connected todrive-sense grounding regions, in other embodiments grounding regionscan be electrically separated from other grounding regions. In otherembodiments, grounding regions can be grounded to other types of ground,such as an AC ground. Grounding regions 1301 and 1303 can help to reducea static capacitance that can form between drive and sense regionsand/or drive and drive regions. Reducing such static capacitances in thetouch system configuration can improve the accuracy and powerconsumption of the touch screen, for example.

FIGS. 14A-16C illustrate another example configuration of multi-functioncircuit elements of display pixels according to embodiments of thedisclosure including a third metal (M3) layer, and illustrate examplemethods for manufacturing the display pixels according to embodiments ofthe disclosure. FIGS. 14A-16C show an example set of three differentdisplay pixels in a side-by-side view simply for ease of comparison, andis not intended to imply a particular ordering of display pixels. FIGS.14A-14C show an example display pixel 1401 in a drive region, such asdisplay pixel 517 described above in reference to FIGS. 5-6. FIGS.15A-15C show an example display pixel 1501 in the sense region with adrive tunnel, such as pixel 515 described in reference to FIGS. 5-6.FIGS. 16A-16C show an example display pixel 1601 in the sense regionwithout a drive tunnel. In the following description, processes andstructures common to all of display pixels 1401, 1501, and 1601 aredescribed with respect to a single display pixel, simply for the purposeof clarity.

FIGS. 14A, 15A, and 16A show earlier stages of processing including afirst stage of forming a poly-silicon layer, including circuit elementsof the transistors. A second stage includes forming gate lines in an M1layer of all display pixels, and forming an xVcom line in the M1 layerof display pixels 1401 and 1501. The xVcom line of display pixel 1401includes an expanded portion at the left side to allow for connection toa yVcom line. The xVcom line of display pixel 1501 acts as a drivetunnel that bypasses the other conductive pathways in the sense regionbecause no connection is made between the xVcom line and the otherconductive pathways of the sense region (i.e., there is a bypass). Next,a connection layer (CON1) is formed including connections on transistorcircuit elements of the display pixels. Display pixel 1401 includes anadditional connection on the expanded xVcom portion. Data lines areformed in the M2 layer of the display pixels, and the M2 layer ofdisplay pixel 1401 includes a yVcom line.

FIGS. 14B, 15B, and 16B show middle stages of processing. For reference,the M2 layer is also shown. A second connection layer (CON2) is formedto connect the transistor drains to a pixel electrode. Display pixel1401 includes another connection in CON2 that connects yVcom to thecommon electrode. Next, the common electrode is formed, for example, ofITO.

FIGS. 14C, 15C, and 16C show later stages of the processing, and showthe Vcom from prior processing for reference. A third metal (M3) layeris formed. The M3 layer of display pixel 1401 is different than the M3layer of display pixels 1501 and 1601, as shown. The M3 layerconfigurations of the sense region display pixels, 1501 and 1601,includes vertical lines that connect to display pixels above and below,thus allowing the sense region display pixels to be connected in they-direction without the use of a yVcom line. Mimicking this M3 structurein the drive region display pixels 1401 can help reduce visualincongruities of the touch screen that may result from the additionalmetal in the sense region. A third connection layer (CON3) is formed andthen display pixel electrodes are formed on all display pixels.

Taken together, FIGS. 14A-C show a display pixel 1401 configured for adrive region similar to display pixel 517 described above. Display pixel1401 includes a gate line 1403 and an xVcom line 1405 in a first metal(M1) layer, and a yVcom line 1407 and data lines 1409 in a second metal(M2) layer. Display pixel 1401 can include a connection such as anx-y-com connection 1411, such as connection 505 described above. Thex-y-com connection 1411 connects xVcom line 1405, yVcom line 1407, witha common electrode (Vcom) 1413.

Taken together, FIGS. 15A-C shows a touch screen display pixel 1501configured for a sense region similar to display pixel 515 describedabove. Display pixel 1501 includes a gate line 1503 and an xVcom line1505 in an M1 layer, and data lines 1507 in an M2 layer. Because xVcomline 1505 is formed in a lower layer of the stackup (M1), and because noconnection is provided between xVcom and yVcom, the xVcom lines “tunnel”horizontally through the sense region display pixel 1501 withoutconnecting to the common electrodes (Vcom) 1513 of the sense region.This is one example of a drive tunnel, which can connect drive regionsthrough a conductive pathway running through the display pixel stackupof another type of region, such as a sense region, while bypassing thatregion, i.e., does not electrically contact with the touch sense circuitelements in the display pixel stackup of the bypassed region. Likewise,in other embodiments, other types of tunnels could be used, such assense tunnels connecting sense regions. FIG. 15C shows a third metal(M3) layer is used, in part, as a connection structure to electricallyconnect display pixel circuit elements in the sense region, in both thex and y directions, as shown by the connection grid 1509. Note thatwhile yVcom is used in drive pixel electrodes 1401, no yVcom is used inthe sense pixel electrodes 1501 and 1601. Rather, y connectivity isprovided by the M3 layer. In some embodiments, the display pixels in thesense region can be connected together in the horizontal directionthrough connections and switches in the border of the touch screen.

Taken together, FIGS. 16A-C show a display pixel 1601 that is identicalto display pixel 1501, except that display pixel 1601 does not include adrive tunnel. Display pixel 1601 does include a connection structure inthe M3 layer to electrically connect display pixel circuit elements inthe sense region, as shown by the connection grid 1603 in FIG. 16C.

FIGS. 17-23 illustrate other example configurations of display pixelsincluding another configuration of a third metal (M3) layer, examplemethods for manufacturing the display pixels, an example touch pixellayout, and an example touch screen according to embodiments of thedisclosure. As with FIGS. 14A-16C above, FIGS. 17-20 illustrate aside-by-side view of an example set of display pixels in differentstages of manufacture simply for ease of comparison. FIGS. 21A and 21Billustrate an example layout of display pixels for one example touchpixel according to embodiments of the disclosure. FIGS. 22-1 and 22-2illustrate an example touch pixel layout that can include example touchpixels such as those shown in FIG. 21A.

Referring to FIGS. 17-20, an example manufacturing processes for displaypixel stackups of a set of eight example display pixels (labeledA_pixel, B_pixel, . . . H_pixel). As explained in more detail below,each of the display pixels in the set is one of three types of displaypixels, a connection layer type, a contact type, and a tunnel type, asdescribed in more detail below. In the following description, processesand structures common to all of display pixels A-H may be described withrespect to a single display pixel, simply for the purpose of clarity.

FIG. 17 shows earlier stages of the example processing including a firststage of forming a poly-silicon layer, including circuit elements of thetransistors 1701. A second stage includes forming gate lines 1703 in anM1 layer of all display pixels, and forming an xVcom line 1705 in the M1layer of display pixels E-H. The xVcom lines of display pixels E-Finclude an expanded portion 1706 at middle sub-pixel to allow forconnection to a common electrode. The xVcom lines of display pixels G-Hact as drive tunnels that bypass the other conductive pathways in thesense region because no connection is made between the xVcom line andthe other conductive pathways of the sense region (i.e., there is abypass). Next, a connection layer (CON1) is formed including connections1707 on transistor circuit elements of the display pixels, and on theexpanded xVcom portion 1706. Data lines 1709 are formed in the M2 layerof the display pixels.

FIG. 18 shows middle stages of the example processing. For reference,the M2 layer is also shown. A second connection layer (CON2) is formedto connect the transistor drains to a common electrode (Vcom) 1805 witha connection 1801. Display pixels E-F include another connection 1803 inCON2 that connects xVcom 1705 to the common electrode 1805. Next, thecommon electrode 1805 may, for example, be formed of a substantiallytransparent conductor, such as ITO.

FIG. 19 shows later stages of the example processing, and shows the Vcom1805 from prior processing for reference. In the processing shown inFIG. 19, a third metal (M3) layer and a third connection layer (CON3)are formed. The CON3 layer 1905 connects to display pixel electrodes.The M3 layer is formed in electrical contact with Vcom 1805. The M3layers of each display pixel includes two vertical lines 1901 and onehorizontal line 1903. In some embodiments, the M3 layer can serve thesame purpose as a yVcom line in other embodiments. In general, in someembodiments the M3 layer can have certain advantages in that it canprovide relatively low cross capacitance coupling between itself and thedata/gate lines. Further, in the sense regions, the horizontal(x-direction) connection of the M3 layer can serve to couple all thesense common electrodes together to enhance the y-direction chargesensing. The x-y connections of the common electrodes in the senseregion can be repeated in the drive region for uniformity. Yet further,by positioning the vertical M3 lines (y-direction) over the data lines,an enhanced aperture ratio may be achieved. Since the drive tunnel canstill be used even with the M3 layer to bypass the sense regions, thehorizontal (x-direction) of the M3 layer can be disposed over the drivetunnel and over any xVcom layer aligned therewith so as to increase theaperture ratio. In pixel embodiments in which no xVcom line is used, thestimulating drive line signal can be fed to the M3 layer. In general,the simulating drive line signal may be fed to one or both of the xVcomline and the M3 layer. Vertical lines 1901 in each display pixel mayinclude y-disconnections or y-connections, depending on the particulardisplay pixel of the set (i.e., A_pixel, B_pixel, etc.). A y-connectionof the B_pixel and a y-disconnection of the C_pixel are highlighted inFIG. 19. Horizontal lines 1903 in each display pixel may includex-disconnections or x-connections, depending on the particular displaypixel of the set. An x-connection of A_pixel and an x-disconnection ofE_pixel are highlighted in FIG. 19. The vertical lines 1901 andhorizontal lines 1903 of the M3 layer of display pixels A, F, and Hextend to the edges (top, bottom, left, and right) of the display pixel,and can potentially connect display pixels A, F, and H to adjacentdisplay pixels in each direction. Thus, display pixels A, F, and Hprovide x- and y-connections (x-con, y-con). Display pixels A, F, and Hare labeled as x- and y-connected display pixels because the horizontalline 1903 of each display pixel forms a conductive pathway betweenadjacent display pixels on the right and left, and vertical lines 1901of each display pixel form a conductive pathway between adjacent displaypixels on the top and bottom. However, while display pixels A, F, and Hhave the connection structure to connect in both the x-direction and they-direction, the display pixels are not necessarily connected toadjacent display pixels because one or more of the adjacent displaypixels can include, for example, a disconnection in the M3 layer thatdisconnects the adjacent display pixel from pixel A, F, or H.

The M3 layer in each of display pixels B, E, and G extends fully in thevertical direction, but does not extend to the right edge of the displaypixel. These display pixels provide x-disconnections and y-connections(x-discon, y-con). More specifically, display pixels B, E, and G are“right disconnected”, i.e., they do not connect to the M3 layers ofdisplay pixels on their right. Likewise, the M3 layer of display pixel Cprovides x-connection and y-disconnection (x-con, y-discon), and morespecifically, pixel C is “bottom disconnected.” The M3 layer of displaypixel D provides x- and y-disconnections (x-discon, y-discon), and morespecifically, pixel D is “right and bottom disconnected”. It should benoted that disconnections are not limited to right and/or bottom, butthere could be disconnections at the top, left, or in the interior ofthe M3 layer of a display pixel, and in any number and combination.

FIG. 20 shows even later stages of the example processing. The M3 andCON3 layers are shown for reference. Display pixel electrodes 2001 andblack masks (BM) 2003 are formed on all display pixels. In FIGS. 17-20,there is no yVcom line connectivity as there is in the embodiment ofFIG. 5. Rather, the M3 layer can serve the purpose of connecting thecommon electrodes in the x and y directions. However, xVcom can still beused in some pixels, i.e., E, F, G, H, to provide a drive tunnel, i.e.,a sense region bypass.

FIGS. 21A & 21B show an example layout of display pixels for one exampletouch pixel 2103. Touch pixel 2103 includes a region of 64×64 displaypixels, each of the display pixels being one of display pixels A-Hdescribed above according to the legend of display pixels shown in thefigure. FIG. 21A also shows an example touch screen 2101 including anexample arrangement of 150 (15×10) touch pixels 2103. The display pixellayout creates groupings of display pixels that can substantiallycorrespond to the drive region segments, sense regions, and groundingregions described above in reference to FIGS. 4 and 13. In particular,the layout of display pixels forms two X regions (X1 and X2), two Yregions (Y1 and Y2), and one Z region. The X1 and X2 regions can be, forexample, a right-half portion of a drive region segment and a left-halfportion of another drive region segment, such as right-half portion 309and left-half portion 313, respectively, in FIG. 3. The Y regions canbe, for example, portions of grounding regions such as drive-sensegrounding region 1301 of FIG. 13. The Z region can be, for example, aportion of a sense region such as sense line 223 of FIG. 3. Theparticular configurations of the set of eight display pixels shown inFIGS. 17-20, along with the particular design pixel layout shown inFIGS. 21A and 21B, creates the grouping of circuit elements that can beused in a touch sensing system to detect touch.

As can be seen in light of the FIGS. 17-20, and the legend of FIG. 21A,display pixels from column 1-23, and display pixels from rows 1-64 areconnected together in the M3 layer to form the drive region X1.Grounding region Y1 includes display pixels of columns 24-25, and rows1-64. Sense region Z includes columns 26-39, rows 1-64. Grounding regionY2 includes display pixels of columns 40-41, and rows 1-64. Drive regionX2 includes columns 42-64, rows 1-64.

Drive regions X1 and X2 are electrically connected together throughcircuit elements of display pixels of drive tunnels (bypasses) 2105.Drive tunnel 2105 includes display pixels E, H, G, and F. Referring toFIG. 20, display pixels E and F provide a “contact” between the M3 layer(at contact points 2005 of FIG. 20) through conductive layers Vcom ITO,CON2, M2, and CON1 to connect with xVcom in the M1 layer, as seen in thefigures. Thus, display pixels E and F allow the M3 layer of a driveregion to bypass a grounding and sense regions by tunneling (creating anout-of-layer/out-of-plane bypass to the xVcom (M1) layer).

Display pixels G and H include circuit element xVcom, and do not includea connection between xVcom and any of the other circuit elements of thedisplay pixels that operate in the touch sensing system described inmore detail below. Thus, display pixels type G and H are examples oftunneling connections that bypass grounding and sense regions to connecttogether two drive regions e.g., drive regions X1 and X2.

Referring again to FIGS. 17-20, the three example types of displaypixels, connection layer type, contact type, and tunnel type, will nowbe described in more detail with reference to the example display pixellayout of FIGS. 21A and 21B. In this example, the common electrodes ofthe display pixels in each region are connected together primarilythrough the M3 layer, which is referred to as a connection layer herein.A_pixels, B_pixels, C_pixels, and D_pixels are connection layer typedisplay pixels, which can serve the common function of connectingtogether the common electrodes of the display pixels through theconnection layer. In particular, as described above vertical lines 1901and horizontal lines 1903 are electrically connected to the commonelectrodes of the display pixels. The four different M3 layerconfigurations of the connection layer type display pixels provide fourdifferent ways to connect the M3 layer between display pixels. A_pixelscan connect the M3 layer in all adjacent display pixels (top, bottom,left, and right). B_pixels can connect to the top, bottom, and left, butprovides a disconnection from display pixels to the right. C_pixels canconnect to the top, left, and right, but provides a disconnection fromdisplay pixels below. D_pixels can connect to the top and left, butprovides a disconnection from display pixels to the right and displaypixels below. Referring to FIG. 21A, the majority of display pixels ofthe display pixel layout can be A_pixels, which typically can be locatedin interior areas of regions to connect all adjacent pixels efficiently.

B_pixels, C_pixels, and D_pixels can be located at the boundaries ofregions because the x- and y-disconnections of these display pixels canprovide the disconnection that forms the boundaries of regions. Forexample, the right-disconnected B_pixels can be arranged in verticallines, as shown in FIG. 21A, to separate regions left and right.C_pixels can be arranged in horizontal lines, as shown in FIG. 21A, toseparate regions above and below. D_pixels can be placed in the cornersof regions to separate regions left and right and above and below.

Using pixels A-D alone, it is possible to form the drive regionsegments, the sense line, and the grounding regions shown in FIG. 21A.In some embodiments of the disclosure, however, drive region segmentsare electrically connected together through conductive pathways thatbypass other regions, such as the grounding regions and the senseregion. The contact type display pixels, i.e., E_pixels and F_pixels,and the tunnel type display pixels, i.e., G_pixels and H_pixels, canform conductive pathways bypassing other regions. The contact typepixels can electrically connect or disconnect two or more conductivelayers in the stackup of the display pixel. The example contact typedisplay pixels described herein include a connection between the M3layer and an xVcom line, which can be formed in a first metal layer (M1layer). Thus, the contact type pixels form an out-of-plane/layer bypassby connecting the connection layer (M3 layer) of a drive region segmentto a different conductive pathway, the xVcom line in the M1 layer. Thetunnel type display pixels include the xVcom line, but do not include aconnection between the xVcom line and any other circuit element of thedisplay pixel stackup, such as the M3 layer.

The bypassing conductive pathways will now be described in more detail.As shown in FIGS. 21A and 21B, touch pixel 2103 includes three drivetunnels 2105. Each drive tunnel 2105 includes display pixels in thefollowing pattern of pixel types: E, H, G, H, . . . H, G, H, G, F. Adrive tunnel 2105 is one example of a bypassing conductive pathway.Starting at the left end of drive tunnel 2105, the bypassing conductivepathway begins with an E_pixel, which includes a right-disconnection inthe connection layer to disconnect the connection layer between thedrive region segment and the grounding region in FIG. 21. Consequently,the right disconnection of the E_pixel results in a+x-disconnection inthe connecting layer between the two drive region segments, and theout-of-plane/layer connection of the E_pixel results in an x-connectionin another layer (M1) between the two drive region segments.

Once the out-of-plane/layer connection to the other layer is made, thebypassing conductive pathway runs through the other regions, i.e., thegrounding regions and the sense region, using the tunnel type displaypixels. The tunnel type display pixels each include the xVcom line andalternatively include an x-disconnection and an x-connect. Morespecifically, the G_pixels include a right disconnection, and theH_pixels include a right connect. The x-connect/disconnect of the tunneltype display pixels can, for example, allow more than one other regionto be formed between the two drive region segments. In particular, asshown in FIG. 21 the G_pixels can be formed in a vertical column ofB_pixels to create disconnections to form the border between groundingregion Y1 and sense region Z, the border between sense region Z andgrounding region Y2, and the border between grounding region Y2 anddrive region segment X2. H_pixels can be located in interior areas ofthe other regions, such as the grounding regions and the sense regionbecause the connection layer (M3 layer) of the H_pixels connects to alladjacent pixels, similar to the A_pixels.

FIGS. 22-1 and 22-2 show an example touch pixel layout and touch screen2201 according to embodiments of the disclosure. Touch screen 2201includes an LCD FPC (flexible printed circuit board) that connects 2201to LCD circuitry (not shown), an LCD drive that drives the displaypixels in a display phase, a Vcom line carrying a common voltage for thetouch screen. The Touch FPC includes the following lines: r0-r14 andr14-r0 lines that transmit drive signals to the drive regions, c0-c9lines that receive sense signals from the sense regions, tswX, tswY, andtswZ (sometimes referred to as “tswX, Y, Z” herein) lines that connectto a touch switch (TSW) that can control various switching, such asswitching from connecting all data lines to a virtual ground in a touchphase to connecting the respective data lines to corresponding dataoutputs from LCD drive during a display phase, switching between senseregions during the touch sense phase, etc. The Touch FPC also includesg1 and g0 lines for connecting data lines and grounding regions,respectively, to virtual grounds. Gate drivers that drive gate lines areincluded.

FIG. 22-2 also shows a side view of touch screen 2201. The side viewillustrates some of the connections in more detail. For example, FIG.22-2 shows M3 connections from Y regions allow those regions to begrounded to g0. M3 connections from Z regions allow the Z regions to beconnected to c0-c9 lines. M2 connections allow data lines to be groundedto g1 during the touch sensing phase.

FIG. 23 is a side view of an example touch screen including a highresistance (R) shield according to embodiments of the disclosure. FIG.23 shows a portion of a touch screen 2300, including a cover 2301, anadhesive 2302, a polarizer 2303, a high resistance (R) shield 2304, acolor filter glass 2305, drive regions 2309, sense region 2313,grounding region 2315, a TFT glass 2316, and a second polarizer 2317.The liquid crystal layer can be disposed below the color filter glass. Ahigh resistance shield, such as high R shield 2304, may be placedbetween a CF glass and a front polarizer in place of a low resistivityshielding layer for a FFS LCD, for example. The sheet resistance of thehigh R shield may be, for example, 200M Ohm/square˜2G Ohm/square. Insome embodiments, a polarizer with high resistivity shielding film maybe used as a high R shielding layer, thus replacing polarizer 2303 andhigh R shield 2304 with a single high R shielding polarizer, forexample. A high R shield may help block low frequency/DC voltages nearthe display from disturbing the operation of the display. At the sametime, a high R shield can allow high-frequency signals, such as thosetypically used for capacitive touch sensing, to penetrate the shield.Therefore, a high R shield may help shield the display while stillallowing the display to sense touch events. High R shields may be madeof, for example, a very high resistance organic material, carbonnanotubes, etc.

FIG. 24 is a partial top view of another example capacitive-typeintegrated touch screen 2400, in accordance with embodiments of thedisclosure. This particular touch screen 2400 is based on selfcapacitance and thus it includes a plurality of touch sensing regions2402, which each represent different coordinates in the plane of touchscreen 2400. Touch pixels 2402 are formed of display pixels 2404 thatinclude multi-function circuit elements that operate as part of thedisplay circuitry to display an image on touch screen 2400 and as partof a touch sensing circuitry to sense a touch on or near the touchscreen. In this example embodiment, the touch sensing circuitry andsystem operate based on self capacitance, thus, the self capacitance ofthe circuit elements in a touch pixel 2402. In some embodiments, acombination of self capacitance and mutual capacitance may be used tosense touch.

Although embodiments of this disclosure have been fully described withreference to the accompanying drawings, it is to be noted that variouschanges and modifications including, but not limited to, combiningfeatures of different embodiments, omitting a feature or features, etc.,as will be apparent to those skilled in the art in light of the presentdescription and figures.

For example, one or more of the functions of computing system 200described above can be performed by firmware stored in memory (e.g. oneof the peripherals 204 in FIG. 2) and executed by touch processor 202,or stored in program storage 232 and executed by host processor 228. Thefirmware can also be stored and/or transported within anycomputer-readable medium for use by or in connection with an instructionexecution system, apparatus, or device, such as a computer-based system,processor-containing system, or other system that can fetch theinstructions from the instruction execution system, apparatus, or deviceand execute the instructions. In the context of this document, a“computer-readable medium” can be any medium that can contain or storethe program for use by or in connection with the instruction executionsystem, apparatus, or device. The computer readable medium can include,but is not limited to, an electronic, magnetic, optical,electromagnetic, infrared, or semiconductor system, apparatus or device,a portable computer diskette (magnetic), a random access memory (RAM)(magnetic), a read-only memory (ROM) (magnetic), an erasableprogrammable read-only memory (EPROM) (magnetic), a portable opticaldisc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flash memory suchas compact flash cards, secured digital cards, USB memory devices,memory sticks, and the like.

The firmware can also be propagated within any transport medium for useby or in connection with an instruction execution system, apparatus, ordevice, such as a computer-based system, processor-containing system, orother system that can fetch the instructions from the instructionexecution system, apparatus, or device and execute the instructions. Inthe context of this document, a “transport medium” can be any mediumthat can communicate, propagate or transport the program for use by orin connection with the instruction execution system, apparatus, ordevice. The transport readable medium can include, but is not limitedto, an electronic, magnetic, optical, electromagnetic or infrared wiredor wireless propagation medium.

What is claimed is:
 1. A stackup of a plurality of display pixels, thestackup comprising: a plurality of gate lines; a plurality of datalines, the plurality of data lines electrically insulated from theplurality of gate lines; a first, second and third region each havingcircuit elements of the display pixels, the third region disposedbetween the first and second regions alone a first direction; andwherein circuit elements of the display pixels in the first region areelectrically connected together in the first direction by a firstplurality of first line portions and the circuit elements of the displaypixels in the first region are electrically connected together in asecond direction by a first plurality of second line portions; circuitelements of the display pixels in the second region are electricallyconnected together in the first direction by a second plurality of firstline portions and the circuit elements of the display pixels in thesecond region are electrically connected together in the seconddirection by a second plurality of second line portions; the firstplurality of first line portions and the first plurality of second lineportions, and the second plurality of first line portions and the secondplurality of second line portions electrically insulated from theplurality of gate lines and the plurality of data lines; and wherein atleast one conductive pathway connects circuit elements of the firstregion to circuit elements of the second region wherein the at least oneconductive pathway crosses one or more display pixels of the thirdregion without electrically connecting to the circuit elements of thethird region.
 2. The stackup of claim 1, wherein the plurality of gatelines are formed from a first deposit of conductive material; theplurality of data lines are formed from a second deposit of conductivematerial and the first plurality of first line portions and the firstplurality of second line portions are formed of by a third deposit ofconductive material.
 3. The stackup of claim 2, wherein the thirddeposit of conductive material is distinct from the first and seconddeposits of conductive material.
 4. The stackup of claim 1, wherein:circuit elements of display pixels in the third region are electricallyconnected together in at least one of the first and second directions.5. The stackup of of claim 1, wherein the circuit elements are commonelectrodes of the display pixels.
 6. The stackup of claim 1, furthercomprising: a fourth region of the display pixels located between thefirst region and the second region, wherein the conductive pathwaycrosses one or more display pixels of the fourth region withoutelectrically connecting to the circuit elements of the fourth region. 7.A touch sensing system comprising the stackup of claim 6 and furthercomprising: a conductive line connecting the fourth region to a ground.8. A touch sensing system comprising the stackup of claim 1, furthercomprising: a drive signal generator connected to one of the first andsecond regions; and a sense channel connected to the third region.
 9. Atouch screen integrated with a display comprising: a plurality ofdisplay pixels arranged along first and second directions; a pluralityof drive lines including some of the plurality of display pixelsdisposed along the first direction and including at least a first andsecond regions of display pixels, each region have circuit elements ofthe display pixels; a plurality of sense lines including others of theplurality of display pixels disposed at least along the seconddirection, crossing the first direction and forming a third region ofdisplay pixels, the third region disposed between the first and secondregions along the first direction; means for interconnecting at leastsome of the circuit elements of the first region along, or substantiallyparallel to, at least the first and second directions; means forinterconnecting at least some of the circuit elements of the secondregion along, or substantially parallel to, at least the seconddirection; means for electrically connecting at least some circuitelements of the first region with circuit elements of the second region,the connecting means electrically bypassing circuit elements of thethird region of circuit elements.
 10. The touch screen as recited inclaim 9, wherein each of the plurality of drive lines includes circuitelements of the display pixels arranged along the first and seconddirections and each of the plurality of sense lines includes circuitelements of the display pixels arranged along the first and seconddirections.
 11. The touch screen as recited in claim 9, wherein thedisplay comprises a liquid crystal display.
 12. The touch screen asrecited in claim 11, wherein the circuit elements of the display pixelsof the first region and the circuit elements of the display pixels ofthe second region comprise common electrodes of the liquid crystaldisplay.
 13. The touch screen as recited in claim 11, wherein the meansfor interconnecting at least some of the circuit elements of the firstregion interconnects common electrodes of the liquid crystal displaywithin the first region along both the first and second directions andthe means for interconnecting at least some of the circuit elements ofthe second region interconnects common electrodes of the liquid crystaldisplay within the second region along both the first and seconddirections.
 14. A computer system comprising: a processor; a memory; adisplay system including display circuitry that includes a plurality ofcircuit elements within display pixels, and a display controller; and atouch sensing system including touch sensing circuitry that includes theplurality of circuit elements grouped into a plurality of first regionsand a plurality of second regions, at least one second regioninterpositioned between each of two successive first regions along afirst direction, and means for electrically connecting circuit elementsof a plurality of first regions while crossing and electricallybypassing the interpositioned second regions; the circuit elements ofeach of the first regions being electrically connected together alongthe first direction and along a second direction, transverse to thefirst direction; and a touch controller.
 15. A touch screen having anintegrated display, the touch screen comprising: a plurality of displaypixels, each having a corresponding circuit element; a plurality offirst lines, each including a plurality of physically distinct firstregions arranged along a first direction, each first region havingcircuit elements of some of the plurality of display pixels connected toone another along both the first direction and a second, differentdirection; a plurality of second lines, each including a second region,each second region having circuit elements of others of the plurality ofdisplay pixels connected to one another along at least one of the firstand second directions, one of the plurality of second regions interposedbetween adjacent pairs of first regions arranged along the firstdirection; a conductive pathway connecting together each adjacent pairof first regions while crossing and electrically bypassing interposedsecond region; the plurality of display pixels configured for displayingdata during a display mode of operation; and the plurality of displaypixels configured for detecting touch by mutual capacitive coupling ofcircuit elements of ones of the plurality of first regions and ones ofthe plurality of second regions.
 16. The touch screen of claim 15wherein the plurality of first lines comprise drive lines and theplurality of second lines comprise sense lines.
 17. The touch screen ofclaim 15 wherein the plurality of first lines comprise sense lines andthe plurality of second lines comprise drive lines.
 18. A method ofmanufacturing an integrated touch screen having a plurality of displaypixels, and circuit elements including common electrodes of the displaypixels, the method comprising: forming a first line segment in a firstregion of the touch screen, the first region including plural displaypixels and the first line segment connecting circuit elements of thedisplay pixels in the first region in a first direction and in a second,different direction; forming a second line segment in a second region ofthe touch screen that is separated from the first region by a thirdregion of the touch screen, the second and third region including pluraldisplay pixels and the second line segment connecting circuit elementsof the display pixels in the second region in the first direction and inthe second direction; and forming a conductive pathway between the firstand second regions, the conductive pathway electrically bypassingcircuit elements of display pixels the third region and electricallyconnecting the first line segment and the second line segment.